FatMouse‘ Trade |
| Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) |
| Total Submission(s): 4555 Accepted Submission(s): 1354 |
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Problem Description
FatMouse prepared M pounds of cat food, ready to trade with the cats guarding the warehouse containing his favorite food, JavaBean.
The warehouse has N rooms. The i-th room contains J[i] pounds of JavaBeans and requires F[i] pounds of cat food. FatMouse does not have to trade for all the JavaBeans in the room, instead, he may get J[i]* a% pounds of JavaBeans if he pays F[i]* a% pounds of cat food. Here a is a real number. Now he is assigning this homework to you: tell him the maximum amount of JavaBeans he can obtain. |
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Input
The input consists of multiple test cases. Each test
case begins with a line containing two non-negative integers M and N. Then N
lines follow, each contains two non-negative integers J[i] and F[i]
respectively. The last test case is followed by two -1‘s. All integers are not
greater than 1000.
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Output
For each test case, print in a single line a real
number accurate up to 3 decimal places, which is the maximum amount of JavaBeans
that FatMouse can obtain.
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Sample Input
5 3 7 2 4 3 5 2 20 3 25 18 24 15 15 10 -1 -1 |
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Sample Output
13.333 31.500 |
刚开始用了一个比较普通的算法：1循环输入数据，2根据“好坏”排序数据，3得到最优解；验证数据正确，可能是这个算法太繁琐导致超时，遗憾不能ac
1 #include<stdio.h> 2 int main() 3 { 4 int m,n,i,s; 5 double j[1005],f[1005],t[1005],tmpt,tmpj,tmpf,cha,max=0; 6 while(scanf("%d%d",&m,&n)!=EOF) 7 { 8 if(m<=0&&n<=0) 9 break; 10 max=0; 11 for(i=0;i<n;i++){ 12 scanf("%lf%lf",&j[i],&f[i]); 13 t[i]=j[i]/f[i]; 14 } 15 for(i=0;i<n-1;i++) 16 for(s=1;s<n;s++) 17 if(t[i]<t[s]) 18 { 19 tmpt=t[i]; tmpj=j[i]; tmpf=f[i]; 20 t[i]=t[s]; j[i]=j[s]; f[i]=f[s]; 21 t[s]=tmpt; j[s]=tmpj; f[s]=tmpf; 22 } 23 24 i=0; 25 while(m) 26 { 27 if(m>=f[i]){ 28 max +=j[i]; 29 m -=f[i]; 30 i++; 31 } 32 else{ 33 cha=m/f[i]; 34 max +=j[i]*cha; 35 m=0; 36 i++; 37 } 38 if(i>=n) 39 break; 40 } 41 printf("%.3f\n",max); 42 i=0;max=0; 43 44 } 45 return 0; 46 }
原文：http://www.cnblogs.com/mm-happy/p/3792444.html